Cryptococcus neoformans

Introduction

The only non-dimorphic fungi (no mycelia) that causes human disease.

Epidemiology

• widely distributed in the soil, foods & excreta of pigeons & other animals
• inhalation into the lung is the portal of entry
• may exist as saprophyte in humans with pre-existing lung disease

Pathology

• infection results in cryptococcosis
• cryptococcosis most commonly presents as subacute or chronic meningitis
• 33-50% of patients with cryptococcosis are immunosuppressed

Laboratory

• Cryptococcus neoformans serology
• Cryptococcus neoformans antigen in serum
• Cryptococcus neoformans rRNA
• India ink preparation of spun CSF sediment
  • India ink can outline the clear capsule around a yeast form

More general terms

• Cryptococcus

Additional terms

• cryptococcosis